Not Applicable.
1. Field of the Invention
This invention relates to a hard surface antimicrobial cleaner with a residual antimicrobial effect, and to hard surface antimicrobial cleaner that inhibits the formation of biofilm on the hard surface.
2. Description of the Related Art
It is well known that the washing of hard surfaces (e.g., glass, tile, porcelain, fiberglass composites, metallic surfaces, ceramic surfaces, laminate surfaces, hard polymeric surfaces) with antimicrobial cleaners can remove many bacteria from the washed surfaces. Removal of the bacteria may be due to surfactants or disinfectants in the cleaner and/or the mechanical action of the wash procedure. Antimicrobial hard surface cleaners have been marketed in a variety of forms for some time. Typically, these hard surface antimicrobial products have been formulated to provide bacteria removal during washing. However, there has been more interest recently in hard surface cleaners that have also been shown to provide a residual effectiveness against bacteria. By residual effectiveness it is meant that bacteria on a surface is killed for some period of time following the washing process. Given the potential severe health impacts of bacteria, there is a continuing search for improved antimicrobial cleaners which provide residual effectiveness versus bacteria.
Hard surfaces may also be prone to the attachment of biofilm, which also may have health impacts. A biofilm consists of cells immobilized on a surface and embedded in an organic polymer matrix of microbial origin. A biofilm is a surface accumulation, which is not necessarily uniform in time or space. A biofilm may be composed of a significant fraction of inorganic or abiotic substances held cohesively by the biotic matrix. A biofilm is a protective matrix for bacteria, with the essential purpose of survival in an environment of limited nutrient supply. Biofilms consist of both host microbes and their extracellular products, usually exopolysaccharides. Microbes have a tendency to form these protective exopolysaccharide matrices after they have adhered to a surface. The formation of biofilm complexes requires only humid conditions and/or water systems and contact with a support surface. With respect to nutrients, a nutrient deficiency in fact may increase the biofilm formation capacity of microbes.
Biofilms generally can be produced by almost all microbes under suitable conditions. The most common biofilm producers belong to the genera Pseudomonas, Enterobacter, Flavobacterium, Alcaligenes, Staphylococcus, Klebsiella and Bacillus. One of the main purposes of natural biofilm formation is for the protection of the host microbes from a hostile environment. As a consequence, there is a combative interaction between microbes in biofilms and biocides such as disinfectants. Further, the sessile mode of bacterial growth in biofilms differs from that of the same bacteria species that are present as planktonic cells in a circulating aqueous medium which interfaces with the biofilm. Because of the ramifications of biofilm formation, there have been proposed techniques to inhibit the growth of biofilm on a surface. For example, surfactants have been added to aqueous systems to inhibit microbial colonization on a surface (see, e.g., U.S. Pat. No. 6,039,965). However, there is a need for a hard surface antimicrobial cleaner that cleans and disinfects a hard surface and thereafter inhibits the formation of biofilm on the hard surface.
Thus, given the potential health impacts of bacteria and biofilm on a surface, particularly in kitchen areas, there is a need for hard surface antimicrobial cleaners which clean and disinfect a hard surface and also provide for residual effectiveness versus bacteria. Further, there is a need for hard surface antimicrobial cleaners which clean and disinfect a hard surface and thereafter inhibit the formation of biofilm on the hard surface.
The foregoing needs are met by a hard surface antimicrobial cleaner according to the invention including a disinfectant and a polysiloxane with at least one poly(oxyalkylene) side chain wherein the cleaner kills bacteria on a hard surface for at least 24 hours after being sprayed onto and wiped from the hard surface. The polysiloxane has the formula:
R1R2R3SiO(R4R5SiO)p(R6QSiO)qSiR3R2R1
in which R1, R2, R4, R5, R6 are identical or different and are a C1-C6 alkyl or phenyl, R3 is identical or different and is C1-C6 alkyl, phenyl or Q, and Q is an ether polyoxyalkylene group of the formula xe2x80x94Rxe2x80x94Oxe2x80x94(Rxe2x80x2O)nRxe2x80x3 where R is a linear or branched C3-C15 alkyl group, (Rxe2x80x2O)n is a poly(ethyleneoxy) and/or poly(propyleneoxy) group, n is a mean value ranging from 5 to 200, Rxe2x80x3 is H or a C1-C6 alkyl group, p is a mean value ranging from 10 to 200, and q is 0 or a mean value ranging from 1 to 200, R3 being Q when q is 0.
In a first version of the invention, the hard surface antimicrobial cleaner includes from about 0.01% to about 20% by weight of the total weight of the cleaner of the disinfectant; from about 0.01% to about 20% by weight of the total weight of the cleaner of the polysiloxane with at least one poly(oxyalkylene) side chain; and from about 0.5% to about 20% by weight of the total weight of the cleaner of a solvent.
In a second version of the invention, the hard surface antimicrobial cleaner includes from about 0.01% to about 20% by weight of the total weight of the cleaner of the disinfectant; from about 0.01% to about 20% by weight of the total weight of the cleaner of the polysiloxane with at least one poly(oxyalkylene) side chain; and from 0.1 to about 20% by weight of the total weight of the cleaner of a sequesterant.
In a third version of the invention, the hard surface antimicrobial cleaner includes from about 0.01% to about 20% by weight of the total weight of the cleaner of the disinfectant; from about 0.01% to about 20% by weight of the total weight of the cleaner of the polysiloxane with at least one poly(oxyalkylene) side chain; and from 0.5 to about 20% by weight of the total weight of the cleaner of a surfactant selected from nonionic surfactants, amphoteric surfactants, sarcosine anionic surfactants, cationic surfactants and mixtures thereof.
In a fourth version of the invention, the hard surface antimicrobial cleaner includes from about 0.01% to about 20% by weight of the total weight of the cleaner of the disinfectant; from about 0.01% to about 20% by weight of the total weight of the cleaner of the polysiloxane with at least one poly(oxyalkylene) side chain; and an organosilane of the formula: A3-xBxSiD wherein A is xe2x80x94OH or a hydrolyzable group, B is an alkyl group of from 1 to 4 carbon atoms, x has a value of 0, 1 or 2, and D is a hydrocarbon group of from 1 to 4 carbon atoms, phenyl, or a nonionic or cationic, substituted-hydrocarbon group containing at least one oxygen or nitrogen group or salts of such substituted-hydrocarbon groups.
In a fifth version of the invention, the hard surface antimicrobial cleaner includes from about 50% to about 99.9% by weight of the total weight of the cleaner of an alkyl alcohol disinfectant; and the polysiloxane with at least one poly(oxyalkylene) side chain, wherein the cleaner inhibits biofilm formation on a hard surface for at least 24 hours after being sprayed onto the hard surface. In the fifth version of the invention, the alkyl alcohol disinfectant is preferably ethanol, n-propanol or isopropanol, and serves to disinfect the hard surface and to distribute the polysiloxane on the hard surface in order to inhibit biofilm formation on the hard surface. All or most of the alkyl alcohol disinfectant may eventually evaporate from the hard surface due to the volatility of the alcohol. The fifth version of the invention may consist essentially of the alkyl alcohol disinfectant, the polysiloxane and water, if desired. Alternatively, the fifth version of the invention may include a solvent, a sequesterant, a surfactant or an organosilane.
It is therefore an advantage of the present invention to provide a hard surface antimicrobial cleaner that may be used to clean and disinfect a hard surface and also provides for residual effectiveness versus bacteria.
It is another advantage of the present invention to provide a hard surface antimicrobial cleaner that may be used to clean and disinfect a hard surface and thereafter inhibits the formation of biofilm on the hard surface.
These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description and appended claims.